binderfs: add extended_error feature entry

Add extended_error to the binderfs feature list, to help userspace
determine whether the BINDER_GET_EXTENDED_ERROR ioctl is supported by
the binder driver.

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20220429235644.697372-4-cmllamas@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>